#include <stdio.h>
/* extern:外部的*/
extern int myadd(int num1, int num2);
extern int myminus(int num1, int num2);
extern int mymulti(int num1, int num2);
extern int mydiv(int num1, int num2);

int main()
{
    int sum = myadd(100, 200);
    printf("sum:%d\n",sum);

    int cha = myminus(100, 200);
    printf("cha:%d\n",cha);

    int res = mymulti(100, 200);
    printf("res:%d\n",res);

    int jie = mydiv(100, 200);
    printf("jie:%d\n",jie);
    return 0;

}